North Korean leader Kim Jong-un probably wants to test the United States' commitment to any nuclear deal when he meets with U.S. President Donald Trump next week, a former U.S. envoy said Tuesday.

Trump and Kim are set for a historic summit in Singapore next Tuesday, a meeting that will focus on dismantling North Korea's nuclear weapons program in exchange for security guarantees for the regime.

"I believe he wants the summit to see the seriousness on the U.S. side," Joseph Yun, former U.S. special representative for North Korea policy, said at a congressional hearing.

His remark comes amid lingering skepticism about Kim's intent to give up a nuclear program that took decades to build and on which the regime has staked its survival.

This file photo shows Joseph Yun, former U.S. special representative for North Korea policy. (Yonhap)

"I do believe the phrase 'getting to know you' that President Trump used ... it's probably exact wording from what the North Koreans want to do," Yun said, referring to Trump's characterization of the summit following a meeting with a North Korean envoy at the White House last week.

"I think this is what Kim Jong-un wants. He is the one who has gotten so far. He has come out onto a major foreign policy stage, so I think he wants to start slow," he added.

Trump has tamped down expectation that the decadeslong standoff over North Korea's nuclear weapons and ballistic missiles will be resolved in one go. That's a shift from earlier statements from within the administration that the U.S. will accept nothing short of immediate denuclearization.

Asked how far he thinks Kim will go at the summit, Yun said the North Korean leader could offer a declaration that he will "eventually" denuclearize when he no longer needs nuclear weapons for deterrence.

This file photo shows Victor Cha, former Asia director on the White House National Security Council. (Yonhap)

Victor Cha, former Asia director on the White House National Security Council, added that the young leader will want to give "as little as he can" and "get as much as he can."

He also said the summit will play to Kim's domestic audience.

"They have announced this engagement with the U.S. is now a part of their national narrative but I don't think it's one based on weakness or a desire to get economic assistance," he told the same hearing. "It's based on strength. They're a nuclear weapons state now. That's why the United States wants to talk to them. That's why Donald Trump is ready to meet with them ... to think they're going to give up that corpus of strength at this meeting would completely contradict the domestic narrative." (Yonhap)